In general, the state of a radio signal received by a radio communication apparatus changes depending on a radio communication environment. For example, the radio signal may include a desired signal from a radio communication apparatus on a transmission side (hereinafter, a transmission side radio communication apparatus) and an interference signal from an interference source. Furthermore, when multiple signal propagation paths are formed, the desired signal may include an advancing wave component (for example, a direct wave component) and delay wave components which are delayed from the advancing wave component.
There is known a radio communication apparatus that includes a receiver having a configuration in which an adaptive array antenna and an adaptive equalizer are serially connected to achieve radio communications adapted to such radio communication environment (e.g., see patent document 1).
The adaptive array antenna has multiple antenna elements and cancels the interference signal contained in the radio signal received by the antenna elements according to an antenna weight. The adaptive equalizer combines the advancing wave component and the delay wave components according to an equalization weight. The antenna weight and the equalization weight (hereinafter abbreviated as “weight” as needed) are calculated by a weight calculator provided to the receiver.
As described above, in the radio communication environment including a delay wave (a delay wave component), the receiver having the configuration in which the adaptive array antenna and the adaptive equalizer are serially connected can maximally improve the signal quality of the received radio signal in such a manner that the adaptive array antenna cancels the interference signal and the adaptive equalizer combines the delay wave components.